Resultados do tratamento cirúrgico da fibrilaçäo atrial crônica / Results of the surgical treatment of chronic atrial fibrillation

RESUMO

Objective - Report clinical experience in surgical treatment of atrial fibrillation (AF) by Cox-maze procedure. Methods - 61 patients underwent surgical treatment for AF. Two had primary AF and 59 AF secondary to heart disease (2 atrial septal defects, 57 mitral). Ages ranged from 20 to 74 years (mean = 49). There were 44 females (72 per cent). The surgical technique employed was Cox 3 without cryoablation. The patients were follow-up in specific at patient clinics and underwent periodical ECG, exercise texts, echocardiogram and Holter monitoring. Results - In-hospital mortality was 4.9 per cent and late mortality 1.6 per cent. A temporary pacemaker was used in 28 (46 per cent) and a definitive in 7 patients (11.4 per cent). On hospital discharge, AF remained in 17 per cent; 63.9 per cent had sinus rhythm, 6.9 per cent atrial rhythm, and 10.3 per cent had pacemaker rhythm. In the last evaluattion, AF was present in 19.5 per cent; (70.5 per cent sinus rhythm, 4 per cent atrial rhythm, 2 per cent atrial tachycardia, and 4 per cent pacemaker rhythm). There was no report of thromboembolic episodes. Chronotropic response was considered adequate in 19 per cent, intermediate in 29 per cent, and inadequate in 42 per cent. In Holter monitoring, the mean heart rate was 82+8 bpm, with a minimum of 57+7 bpm and maximum of 126+23 bpm, with supraventricular extrasystoles in 2.3+5.5 per cent of the total hearbeats and ventricular extrasystoles in 0.8+0.5 per cent. In the echocardiogram, the A wave was present in the left atrium in 87.5 per cent. Conclusion - Maze procedure is effective and has acceptable surgical risk. Atrial or sinus rhythms remain stable with a small but remarkable frequency of atrial and ventricular arrhythmias. Left atrial contraction is present, although attenuated, as well as the chronotropic response to exercise.